Convertible liquid spray nozzle

ABSTRACT

A nozzle for a paint or other liquid spray gun operable by pressurized air is provided. The nozzle includes an elongated body having first and second tapered fluid passages extending therethrough for receiving paint and pressurized air, respectively. The passages terminate in exit openings at the front of the body. A hollow cap including a spray opening is mounted at the front of the body to provide a chamber for receiving pressurized air emerging from the second passage and directing the air toward paint emerging from the first passage to produce a paint spray. The nozzle includes two (a) interchangeable caps which permit the paint and pressurized air to mix internally or externally of the chamber.

United States Patent 11 1 1111 3,905,554

Bell Sept. 16, 1975 CONVERTIBLE LIQUID SPRAY NOZZLE 2,880,940 4 1959 Briggs 239 415 3,157,360 11/1964 Heard.... 239/415 X [75] Inventor: Jmathan Durand Towson 3,455,513 7/1969 Wyse 239/423 x [73] Assignee: The Black and Decker Manufacturing Company, Towson, Primary ExaminerJohn J. Love Md. Attorney, Agent, or Firm-Joseph R. Slotnik; Edward L 22 Filed: 0611. 24, 1973 D Murphy eonard Bloom [21] Appl. NO.Z 409,190 57 ABSTRACT A nozzle for a paint or other liquid spray gun operable [52] US. Cl 239/424; 239/417.5 by pressurized air is provided, The nozzle includes an [51] Int. Cl. B05B 07/06 elongated body having first and second tapered fluid 1 Field Of Search 398, passages extending therethrough for receiving paint and pressurized air, respectively. The passages termi- 423 nate in exit openings at the front of the body. A hollow cap including a spray opening is mounted at the 1 References Cited front of the body to provide a chamber for receiving UNITED STATES PATENTS pressurized air emerging from the second passage and 791,617 6/1905 Fesler 239 414 directing the air towardPaim emerging from F first 1,268,232 6/1918 purmanw 239/415 passage to produce a paint spray. The nozzle includes 1,382,640 /1921 Heinrich 239 415 two (a) interchangeable caps which permit the paint 1,382.64] 6/ 1921 Heinrich.. 239/415 X and pressurized air to mix internally or externally of 2,372,678 4/1945 McKay 239/342 the chamber 2,659,628 11 1953 Beach 239/414 2,793,016 5 1957 Aghnides 239/391 2 Claims, 6 Drawing Flgul'es I i ;L::: I 1

PATENTEU SEP 1 6 I975 SHEET 1 0F 2 l i m g p? PATENTED SEPI 61975 SHEET 2 UP 2 MGR CONVERTIBLE LIQUID SPRAY NOZZLE The present invention relates to a liquid spray nozzle and, more particularly, to a nozzle for, for example, a paint spray gun operable by pressurized air.

In the art of paint spray apparatus, paint spray guns have been developed which include nozzles for ejecting a paint spray.- The prior art nozzles have, however, been complicated in structure and, therefore, difficult and expensive to manufacture. Typically, the nozzles have required multiple drilling operations in the nozzle fabrication. In addition, because of the complicated structure, the prior art nozzles have been prone to clog during painting operations. Further, the complicated structure of the nozzles has made it difficult to clean the nozzles after painting operations.

The tendency of the prior art nozzles to clog has been exceptionally acute in the case of heavy bodied paints, such as latex base paints. Consequently, during spray operations with latex paints, it has been necessary to frequently interrupt the painting operations for cleaning of the nozzles.

Because of the difficulty of cleaning the prior art nozzles, it has been common practice to dispose of a used nozzle after each painting operation and to replace it with a new nozzle. A serious disadvantage of this practice is that the continuous disposal and replacement of paint spray nozzles has been extremely expensive be cause of the complicated structure and resultant high cost of manufacture of the prior art nozzles.

In view of the recent development of inexpensive compressed air sources for general use, it has become desirable to provide paint spray apparatus operable by pressurized air for general applications, including home use. To avoid the disadvantages occurring in the prior art because of the complicated nozzle designs, and the prohibitive expense resulting from the requirement of replacing complicated nozzle structures, it is necessary to provide a paint spray nozzle having an internal structure which is readily accessible for cleaning. A nozzle capable of use with both light bodied and heavy bodied paints is particularly useful. It is also extremely desirable to provide a nozzle which can be manufactured by inexpensive conventional techniques, such as molding.

It is an object of the present invention to provide a nozzle for a paint spray gun which is operable by pressurized air.

It is also an object of the present invention to provide a paint spray nozzle incorporating an unrestricted internal flow structure to minimize the tendency of the nozzle to clog.

It is another object of the present invention to provide a nozzle for a paint spray gun which can be readily disassembled to provide easy access to the internal nozzle structure for cleaning.

It is also another object of the present invention to provide a paint spray nozzle capable of internal mix or external mix operation to adapt the nozzle for use with various types of paints.

it is a further object of the present invention to provide a nozzle for a paint spray gun which can be formed by inexpensive manufacturing techniques, such as molding.

The present invention provides a paint spray nozzle which comprises a body including first and second fluid passages extending therethrough for receiving paint and pressurized air, respectively, with the fluid passages terminating in adjacent exit openings provided on the body. The nozzle includes means in fluid communication with the first fluid passage for supplying paint to the first fluid passage and means in fluid communication with the second fluid passage for supplying pressurized air to the second fluid passage. In addition, the nozzle includes a cap mounted on the body and having a hollow interior to provide a chamber for receiving pressurized air from the exit opening of the second fluid passage and directing the air toward the exit opening of the first fluid passage. A spray opening extends through the cap from the chamber to form a paint spray from paint and pressurized air supplied to the first and second fluid passages, respectively.

A preferred embodiment of the paint spray nozzle comprises an elongated body including a first tapered passage extending longitudinally therethrough for receiving paint and a second tapered passage extending longitudinally therethrough for receiving pressurized air. A front end of the body comprises a flat, circular face provided with a cone-shaped extension located on the face including a tip projecting forward from the face. The first tapered passage extends from a separate, larger entrance opening formed at a rear end of the body through the cone-shaped extension to a smaller exit opening provided at the tip of the cone-shaped extension. The second tapered passage extends from a larger, entrance opening at the rear end of the body to a smaller exit opening in the face at the front end of the body. The body also includes an inlet port in fluid communication with the first tapered passage for supplying paint to the first tapered passage.

In addition, the preferred embodiment of the nozzle includes a removable cap mounted on the front end of the body adjacent to its face. The cap has a hollow, cone-shaped interior which, in cooperation with the face and cone-shaped extension of the body, provides a chamber at the front end of the body for receiving pressurized air emerging from the exit opening of the second passage and directing the air toward the tip of the extension. A spray opening extends through the cap in alignment with the exit opening of the first passage at the tip to form a paint spray from paint and pressurized air supplied to the first and second passages, respectively. Preferably, two interchangeable caps are provided to adapt the nozzle for either internal or external mixing of paint and pressurized air.

In the internal mix embodiment, the cap includes a tapered front wall provided with a cone-shaped interior surface which terminates in a central opening located in front of the tip of the cone-shaped extension in axial alignment with the exit opening in the tip. The coneshaped interior surface of the cap, in cooperation with the face and cone-shaped extension of the body, provides a mixing chamber for receiving paint and pressurized air. The tip of the cone-shaped extension is located within the mixing chamber. Paint and pressurized air supplied to the fluid passages are mixed internally in the chamber and ejected from the central opening to produce a paint spray. The internal mix embodiment is particularly suitable for use with slow drying liquids or those which will, after drying, redissolve in the solution being sprayed. Examples of these are oil base paints, stains, varnishes and water solutions, e.g., garden sprays.

In the external mix embodiment, the cap is again provided with a tapered front wall having an interior, coneshaped surface which terminates in a central opening in axial alignment with the exit opening formed in the tip of the cone-shaped extension. The cone-shaped interior surface of the cap, in cooperation with the face and cone-shaped extension of the body provides a chamber for receiving pressurized air and directing the air toward the tip. The central opening in the cap surrounds the tip to define an annular orifice through which pressurized air emerges from the chamber. Paint and pressurized air supplied to the fluid passages are mixed in front of the tip to produce a paint spray. The external mix embodiment is particularly suitable for use with quick drying liquids, such as latex base paints and lacquers.

The present invention provides a nozzle which is readily disassembled to permit easy access for cleaning. The tapered fluid passages of the body provide an unrestricted internal flow structure which minimizes the tendency of the nozzle to clog and is readily accessible for cleaning of the nozzle. The interchangeable caps permit use of the nozzle with either light bodied or heavy bodied paints. In addition, it is possible to fabricate the nozzle by conventional molding techniques to minimize its cost of manufacture.

The accompanying drawings illustrate preferred embodiments of the invention and, together with the description, serve to explain the principles of the inventlon.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a disassembled, side elevation of an internal mix paint spray nozzle comprising a body, a cap, a removable plug, and a plug retainer constructed according to the principles of the present invention;

FIG. 2 is a side elevation, in section, showing the assembled relationship of the body, cap, plug and plug retainer of the nozzle of FIG. 1;

FIG. 3 is a front elevation of the body of the nozzle taken along line 33 of FIG. 1;

FIG. 4 is a rear elevation of the body of the nozzle taken along line 44 of FIG. 1;

FIG. 5 is a side elevation, in section, showing the assembled relationship of the body, cap, plug, and plug retainer of an external mix paint spray nozzle constructed according to the principles of the present invention; and

FIG. 6 is an enlarged front elevation of the nozzle of FIG. 5.

Referring to FIG. 1, the internal mix nozzle comprises, in general, an elongated body 10, a cap 12, a plug 14 and a plug retainer 16. Body 10 is provided with a first set of external threads 18 adjacent to its front end. Cap 12 is generally cylindrical in shape and provided with internal threads (shown in FIG. 2) for engaging external threads 18 to secure the cap to the body. Cap 12 has a knurled exterior surface to facilitate manual threading of the cap on external threads 18. In addition, body 10 is provided with a second set of external threads 20 adjacent to its rear end. Plug retainer 16 is generally annular in shape and provided with internal threads (shown in FIG. 2) for engaging external threads 20 to secure the plug retainer to the body and to hold plug 14 against the rear end of the body. Plug retainer 16 has a knurled exterior surface to facilitate manual threading of the plug retainer on external threads 20.

in accordance with the invention, the body includes first and second fluid passages extending therethrough for receiving paint and pressurized air, respectively. The fluid passages terminate in adjacent exit openings provided on the body. As shown in FIG. 2, elongated body 10 includes first and second tapered passages 22 and 24, respectively, extending longitudinally through the body. Referring to FIGS. 2 and 4, body 10 includes a key-shaped recess 26 formed at its rear end. Fluid passage 22 extends from a first, enlarged entrance opening 28 (FIG. 4) formed in the recess and gradually tapers as it extends toward the front end of body 10. Similarly, fluid passage 24 extends from a second, enlarged entrance opening 30 formed in the recess and tapers gradually as it extends toward the front end of the body.

Referring to FIGS. 2 and 3, the front end of body 10 comprises a flat, circular face 32 provided with a coneshaped extension 34 projecting forward from the face. Cone-shaped extension 34 is centrally located on circular face 32 of the body and terminates in a cylindrical tip 36. Fluid passage 22 extends from larger entrance opening 28 (FIG. 4) through body 10 and its cone shaped extension 34 and terminates in a smaller exit opening 38 (FIG. 3) in cylindrical tip 36. Similarly, fluid passage 24 extends from larger entrance opening 30 (FIG. 4) through body 10 to a smaller exit opening 40 (FIG. 3) in circular face 32.

. In accordance with the invention, the nozzle includes means in fluid communication with the first fluid passage for supplying paint to the first fluid passage to produce a flow of paint emerging from its exit opening. In the preferred embodiment, this means comprises an inlet port in the body in fluid communication with the first fluid passage. Referring to FIG. 2, body 10 is provided with a stem 42 projecting laterally from the body. A passageway 44 extends through stem 42 into fluid communication with passage 22. Passageway 44 includes an enlarged diameter section 46 which extends inwardly from the outer end of stem 42 and a reduced diameter section 48 which begins approximately midway between the outer end of the stern and passage 22 to provide an annular ledge 50.

A conduit 51 for supplying paint to the nozzle is inserted in enlarged diameter portion 46 of passageway 44. Annular ledge 50 limits the extent to which the conduit can be inserted into the passageway. The conduit is in fluid communication with a container (not shown) which contains paint and pressurized air. A manually operable valve (not shown) is provided in the conduit to control the flow of paint from the container to the nozzle.

In accordance with the invention, the cap is mounted on the body and provided with a hollow interior to establish a chamber for receiving pressurized air from the exit opening of the second fluid passage and directing the air toward the exit opening of the first fluid passage. A spray opening extends through the cap to form a paint spray from paint and pressurized air supplied to the fluid passages. Referring to FIGS. I and 2, cylindrical cap 12 includes a tapered front wall 52 provided with a cone-shaped interior surface 54 which, in cooperation with flat, circular face 32 and cone-shaped extension 34 of body 10, provides a mixing chamber for paint and pressurized air. The front wall of cap 12 includes a central opening 56 in axial alignment with exit opening 40 of fluid passage 22 in cylindrical tip 36 of the cone-shaped extension to form a paint spray from paint and pressurized air supplied to the mixing chamber.

As shown in FIG. I, plug 14 includes a key-shaped front face 57 adapted to be received in key-shaped recess 26 (FIGS. 2 and 4) in the rear end of body to cover and seal entrance openings 28 and 30 of fluid passages 22 and 24, respectively. The peripheral outline of key-shaped face 57 corresponds to the shape of recess 26 illustrated in FIG. 4.

In accordance with the invention, the nozzle includes means in fluid communication with the second fluid passage for supplying pressurized air to the second fluid passage to produce a flow of air emerging from its exit opening. In the preferred embodiment, this means comprises a passageway extending through the plug in fluid communication with the entrance opening of the second fluid passage. As shown in FIG. 2, plug 14 includes a cylindrical inlet member 58 extending rearwardly from the plug. A passageway 60 extends through the cylindrical member into fluid communication with enlarged opening 30 (FIG. 4) of fluid passage 24. A conduit 61 connected to a source of pressurized air (not shown) is attached to inlet member 58 to supply pressurized air to fluid passage 24. In addition, plug 14 includes a plug-like projection 62 extending forwardly from its front face 57. Pluglike projection 62 is tapered and shaped to be received in entrance opening 28 of fluid passage 22 to help seal the opening.

Referring to FIG. 2, plug retainer 16, which is generally annular in shape, includes a rear wall 64 provided with a circular opening 66 to permit inlet member 58 to extend beyond the plug retainer. As shown in FIG. 2, rear wall 64 of plug retainer 16 engages the outer edge of plug 14 to retain the plug in engagement with the rear end of body 10 and the key-shaped face 57 in sealing relationship with openings 28, 30.

In the operation of the internal mix paint spray nozzle, pressurized air is continuously supplied to the nozzle via conduit 61. The pressurized air flows into passageway 60 through fluid passage 24 and out of exit opening 40 (FIG. 3) into the mixing chamber defined by the hollow interior of cap 12 and the front end of body 10. The air in the mixing chamber is directed along the cone-shaped exterior surface of extension 34 and cone-shaped interior surface 54 of the cap toward cylindrical tip 36.

In addition, paint is supplied under pressure to the nozzle via conduit 51. As mentioned above, the flow of paint through conduit 51 is controlled by a manually operable valve (not shown). The paint flows into passageway 44 through fluid passage 22 and out of exit opening 38 (FIG. 3) at cylindrical tip 36. As the paint emerges from exit opening 38, it is combined with the air flowing through the mixing chamber and is ejected with the air through spray opening 56 to form a paint spray.

Referring to FIG. 5, the external mix nozzle includes an elongated body 10, a plug 14, and a plug retainer 16 identical to the corresponding components of the internal mix nozzle of FIG. 2. Thus, the same reference numerals have been used to identify these structural elements of the external mix nozzle.

In addition, the external mix nozzle includes a cap 112 which is generally cylindrical in shape and provided with internal threads for engaging external threads 18 to secure the cap to the body. Cap 112 has a knurled exterior surface to facilitate manual threading of the cap on external threads 18.

As shown in FIG. 5, cylindrical cap 112 includes a tapered front wall 152 provided with a cone-shaped interior surface 154 which, in cooperation with flat circular face 32 and cone-shaped extension 34 of body 10, provides a chamber for receiving pressurized air from the exit opening of fluid passage 24 and directing the air toward the exit opening of fluid passage 22 in cylindrical tip 36. The front wall of cap 112 includes a central opening 156 in axial alignment with the exit opening of fluid passage 22. Cylindrical tip 36 extends into central opening 156 to define an annular orifice 158 (FIG. 6) surrounding the cylindrical tip.

In the operation of the external mix paint spray nozzle, pressurized air is continuously supplied to the nozzle via conduit 61. The pressurized air flows into passageway through fluid passage 24 and out of exit opening 40 (FIG. 3) into the chamber defined by the hollow interior of cap 112 and the front end of body 10. The air in the chamber is directed along the coneshaped exterior surface of extension 34 and coneshaped interior surface 154 of the cap through annular orifice 158 toward cylindrical tip 36.

In addition, paint is supplied under pressure to the nozzle via conduit 51. As mentioned above, the flow of paint through conduit 51 is controlled by a manually operable valve (not shown). The paint flows into passageway 44 through fluid passage 22 and out of exit 38 (FIG. 3) at cylindrical tip 36. As the paint emerges from exit opening 38, it is combined with the air emerging from annular orifice 158 to produce a paint spray.

The body, cap, plug, and plug retainer of the nozzle are preferably formed of a suitable plastic material to which paint does not readily adhere, e.g., an acetal polymer. This type of material enables the nozzle to be readily cleaned. In addition, the removable plug permits easy access to the tapered passages and the removable cap permits easy access to the chamber to facilitate cleaning of the nozzle.

The interchangeable caps permit the nozzle to be readily adapted for use with either quick drying or slow drying liquids. The provision of unrestricted tapered passages minimizes the possibility of clogging, particularly in the case of heavy bodied paints. The tapered passages also allow the body of the nozzle to be manufactured by molding techniques using removable pins rather than expensive drilling operations. The capability of manufacturing the nozzle by molding permits the nozzle to be manufactured at minimum cost.

The invention in its broader aspects is not limited to the specific details shown and described, and modifications may be made in the details of the nozzle without departing from the principles of the present invention. For example, although reference has been made to paint spray nozzles, it will be understood that this phraseology is intended to encompass spray nozzles for a variety of liquids.

I claim:

1. A nozzle for paint spray gun operable by pressurized air, comprising:

an elongated body having a rear end and a front end which comprises a flat, circular face provided with a cone-shaped extension centrally located on said face including a tip projecting forward from said face, said elongated body including a first tapered passage extending longitudinally therethrough from a first entrance opening in said rear end through said cone-shaped extension to a first exit opening in said tip of said cone-shaped extension and a second tapered passage extending longitudinally therethrough from a second entrance opening in said rear end to a second exit opening in said face, said body including a stem projecting laterally from said elongated body and including a passageway extending therethrough in fluid communication with said first tapered passage to provide said inlet port for supplying paint to said first tapered passage,

plug means for sealing said first entrance opening;

said elongated body further including an inlet port extending transversely therethrough in fluid communication with said first tapered passage for supplying paint to said first tapered passage to produce a flow of paint emerging from said first exit openan air inlet in fluid communication with said second entrance opening for supplying pressurized air to said second tapered passage to produce a flow of air emerging from said second exit opening; and

a generally cylindrical cap removably mounted on said front end of said elongated body, said cap including a front wall provided with a cone-shaped interior surface which in cooperation with said face and said cone-shaped extension of said elongated body provides a chamber for mixing paint and pressurized air emerging from said first and second exit openings, respectively, said front wall of said cap including a central opening in front of and in axial alignment with said first exit opening in said tip of said cone-shaped extension to form a paint spray from paint and pressurized air supplied to said first and second tapered passages, respectively.

2. A nozzle for a paint spray gun operable by pressurized air, comprising:

an elongated body having a rear end and a front end which comprises a flat, circular face provided with a cone-shaped extension centrally located on said face including a cylindrical tip projecting forward from said face, said elongated body including a first tapered passage extending longitudinally therethrough from a first entrance opening in said rear end through said cone-shaped extension to a first exit opening in said cylindrical tip and a second tapered passage extending longitudinally therethrough from a second entrance opening in said rear end to a second exit opening in said face, said body including a stem projecting laterally from said elongated body and including a passageway extending therethrough in fluid communication with said first tapered passage to provide said inlet port for supplying paint to said first tapered passage; plug means for sealing said first entrance opening; said elongated body further including an inlet port extending transversely therethrough in fluid communication with said first tapered passage for supplying paint to said first tapered passage to produce a flow of paint emerging from said first exit opening; an air inlet in fluid communication with said second entrance opening for supplying pressurized air to said second tapered passage to produce a flow of air emerging from said second exit opening; and a generally cylindrical cap removably mounted on said front end of said elongated body, said cap including a front wall provided with a cone-shaped interior surface which in cooperation with said face and said cone-shaped extension of said elongated body provides a chamber for receiving pressurized air emerging from said second exit opening and directing the air toward said cylindrical tip, said front wall of said cap including a central, circular opening in axial alignment with said first exit opening, said cylindrical tip extending into said circular opening to define an annular orifice around said cylindrical tip through which air exits from said chamber to be mixed with paint emerging from said first exit opening to produce a paint spray. 

1. A nozzle for paint spray gun operable by pressurized air, comprising: an elongated body having a rear end and a front end which comprises a flat, circular face provided with a cone-shaped extension centrally located on said face including a tip projecting forward from said face, said elongated body including a first tapered passage extending longitudinally therethrough from a first entrance opening in said rear end through said cone-shaped extension to a first exit opening in said tip of said cone-shaped extension and a second tapered passage extending longitudinally therethrough from a second entrance opening in said rear end to a second exit opening in said face, said body including a stem projecting laterally from said elongated body and including a passageway extending therethrough in fluid communication with said first tapered passage to provide said inlet port for supplying paint to said first tapered passage; plug means for sealing said first entrance opening; said elongated body further including an inlet port extending transversely therethrough in fluid communication with said first tapered passage for supplying paint to said first tapered passage to produce a flow of paint emerging from said first exit opening; an air inlet in fluid communication with said second entrance opening for supplying pressurized air to said second tapered passage to produce a flow of air emerging from said second exit opening; and a generally cylindrical cap removably mounted on said front end of said elongated body, said cap including a front wall provided with a cone-shaped interior surface which in cooperation with said face and said cone-shaped extension of said elongated body provides a chamber for mixing paint and pressurized air emerging from said first and second exit openings, respectively, said front wall of said cap including a central opening in front of and in axial alignment with said first exit opening in said tip of said cone-shaped extension to form a paint spray from paint and pressurized air supplied to said first and second tapered passages, respectively.
 2. A nozzle for a paint spray gun operable by pressurized air, comprising: an elongated body having a rear end and a front end which comprises a flat, circular face provided with a cone-shaped extension centrally located on said face including a cylindricaL tip projecting forward from said face, said elongated body including a first tapered passage extending longitudinally therethrough from a first entrance opening in said rear end through said cone-shaped extension to a first exit opening in said cylindrical tip and a second tapered passage extending longitudinally therethrough from a second entrance opening in said rear end to a second exit opening in said face, said body including a stem projecting laterally from said elongated body and including a passageway extending therethrough in fluid communication with said first tapered passage to provide said inlet port for supplying paint to said first tapered passage; plug means for sealing said first entrance opening; said elongated body further including an inlet port extending transversely therethrough in fluid communication with said first tapered passage for supplying paint to said first tapered passage to produce a flow of paint emerging from said first exit opening; an air inlet in fluid communication with said second entrance opening for supplying pressurized air to said second tapered passage to produce a flow of air emerging from said second exit opening; and a generally cylindrical cap removably mounted on said front end of said elongated body, said cap including a front wall provided with a cone-shaped interior surface which in cooperation with said face and said cone-shaped extension of said elongated body provides a chamber for receiving pressurized air emerging from said second exit opening and directing the air toward said cylindrical tip, said front wall of said cap including a central, circular opening in axial alignment with said first exit opening, said cylindrical tip extending into said circular opening to define an annular orifice around said cylindrical tip through which air exits from said chamber to be mixed with paint emerging from said first exit opening to produce a paint spray. 